I was trying to Undo one of the tight rear wheel nuts on my car (was in a rush) the sochet slipped and smashed my head on the tray was out for a few seconds and small gash..

Have driven off with the weber fuel jet caps off rrolling around in the engine bay...

Have had a huge amount of smoke coming out of engine bay after dodgey thermo wiring..

A non-mechanical thing was i filled my dads 120Lfuel tank landcruiser with un-leaded petrol when it was a diesiel motor!!...so i had fun pushing it to parking area and dropping all the fuel out the next morning and having to dump it all!!....I just wasnt thinking that nite, so used to filling with pertol for so many years!!

Will update when i can tihnk of other stupid things lol...trust me there is plenty